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Session-Expires and 422

Session timers name who refreshes the dialog, and 422 tells the caller the interval was below Min-SE.

Learn in 5 minutes

  1. Read Session-Expires and the refresher parameter
  2. Retry after 422 using the Min-SE from the response
  3. Refresh with re-INVITE or UPDATE before the interval ends

Visual

422, then a longer interval · study drawing · cyphermonkeylabs.com UAPeer INVITE 422 ACK INVITE 200

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Min-SE is a floor. The absolute minimum in the specification is 90 seconds.

Worked example

Read the 422 The response tells you the floor. The next INVITE has to meet it.

  1. Dissect the 422.
  2. Read Min-SE.
  3. Note the status code class.

Fault

Both sides agreed Session-Expires 1800 refresher=uac. At 1800 seconds the UAS sends BYE. No re-INVITE or UPDATE is in the trace.

The parameter named the UAC. The interval expired with no re-INVITE or UPDATE.

Quiz

Session timers are defined in


422 means


The lowest Min-SE the specification allows is


refresher=uac means


The refresh method is


The ACK of the 422 uses


Ecosystem

Glossary, sister systems, and the integration seam for this room.

CRM Screen pop uses data the contact center already has: ANI, DNIS, case id. Those values may arrive in SIP headers or in a CTI event after the call is up. The CRM is not a SIP element.

Glossary · Ecosystem map · Ports · Troubleshooting

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